Correlation Study Between Dopamine D2 Receptor Gene TaqI Polymorphism And Parkinson's Disease

Parkinson's disease ( PD) is a degenerative disorder of the central nervous system. As one of the main incentive factors of deformity, PD is a frequently-occurring disease in middle and old age people[0]. The symptoms of PD result from the loss of pigmented dopaminergic neurons of the brain. These neurons project to the striatum and their loss leads to reduction of dopamine. Although there were a lot of studies about PD, the pathogeny of PD is not clear yet. Aging familial inheritance and complex environmental factors seem like associate with PD. It was reported that dopamine receptor (DR) agonists have been used to relieve symptoms. Due to the significance of dopamine D2 receptor(DRD2) on pharmacology and physiology, genes encoding proteins involved in dopaminergic transmission have attracted more interest during the evaluation of candidate genes of PD. In this research, we try to investigate the relationship of DRD2 allelic variant and genetic susceptibility of PD patients in the people of Han nationality in Hebei province. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is employed to compare the polymorphism of DRD2 gene TaqI site of PD patients and control groups. And the association between the DRD2 TaqIA and TaqIB polymorphisms and PD is also detected.Objective:To detect the relationship between polymorphism of DRD2 gene TaqI site and susceptibility of the people of Han nationality in Hebei province suffering from PD.Methods:166 PD patients were divided into early-onset subgroup (aged≤50 years) and late-onset subgroup (aged >50 years). 170 healthy people were selected as controls. The difference of DRD2 gene TaqI site polymorphism between PD patients and normal controls were anlysised by PCR-RFLP. The PD patients were further grouped according to age and sex. The difference between early-onset group, late-onset group and the controls, between the male PD group, female PD group and controls, and between male PD group and femal PD group were also compared.Results: It was observed that there was no significant difference of the polymorphism of DRD2 gene TaqI site between PD patients and controls (P﹥0.05). From the results of group investigation, it was found that the DRD2 gene TaqI polymorphisms didn't depend on early-onset and late-onset (P﹥0.05). And it was also no difference between healthy controls and PD patients which were divided into groups by sexes respectively (P﹥0.05). Comparison of male and female PD patients, DRD2 gene TaqI polymorphisms did not show significant difference (P﹥0.05).Conclusion:The results of present study suggest that the hypothesis of genetic susceptibility in PD is not associated with the DRD2 gene TaqI site polymorphisms examined in PD patients in the people of Han nationality in Hebei province.